1. Technical Field
The present invention relates to the technical field of onboard batteries each having a battery module and a high-voltage device disposed in a housing case.
2. Related Art
Onboard batteries are installed in various vehicles, such as automobiles, in order to supply electric power to motors and other various electrical components.
In recent years, in particular, vehicles such as electric vehicles (EV), hybrid electric vehicles (HEV), and plug-in hybrid electric vehicles (PHEV) have gained widespread use. In these electricity-driven vehicles, onboard batteries having a high electricity-storage function are installed.
Onboard batteries each include a battery module and a high-voltage device housed in a housing case. The battery module is configured by, for instance, arranging battery cells (secondary batteries), such as nickel hydrogen batteries or lithium ion batteries. Instances of the high-voltage device to be installed include inverters and DC/DC converters.
In some onboard batteries to be installed in an electric vehicle or the like, in order to retain a high electricity-storage function, battery modules are disposed in the housing case and battery cells in each of the battery modules are connected in series or in parallel.
Some of these onboard batteries are disposed, for instance, in the cargo room formed in the back of a vehicle, and have a battery module and a high-voltage device respectively disposed, for instance, on the upper and lower shelves in a housing case (e.g., Japanese Patent No. 5206110).
The onboard battery described in Japanese Patent No. 5206110 is partly inserted into a disposition depression having an upward opening in a floor panel, and is located between rear side frames of a vehicle body, which are provided apart from each other in the transversal direction.
Once heat is generated and the temperature rises in the high-voltage device and the battery module of the above-described onboard battery, the heat can cause the high-voltage device and the battery module to be inappropriately driven. Accordingly, it is necessary to cool the high-voltage device and the battery module to prevent the temperature from rising.
Incidentally, an onboard battery has a cover body attached to a housing case in which a battery module and a high-voltage device are housed, and the battery module and the high-voltage device are covered with the cover body. Accordingly, the poor performance of the onboard battery for emitting cooling wind from the internal space of the housing case can cause heat to stay (i.e., what is called accumulated heat), resulting in the malfunction of the high-voltage device.
It is possible in this case to dispose, outside the housing case, the high-voltage device to be disposed at the position of accumulated heat. Disposing the high-voltage device outside the housing case, however, requires not only the cover body, but also shielding countermeasures against electromagnetic noise generated when the high-voltage device is driven. All the higher cost then has to be paid. Further, disposing the high-voltage device outside the housing case can lead to an electric shock caused by contact with the high-voltage device.